Add object lifetimes (invalidate references, free listeners)

include/luak/kiwmi_lua_callback.h

@@ -20,7 +20,5 @@ struct kiwmi_lua_callback {
 };
 
 int luaK_kiwmi_lua_callback_new(lua_State *L);
-int luaK_kiwmi_lua_callback_register(lua_State *L);
-void luaK_kiwmi_lua_callback_cleanup(struct kiwmi_lua *lua);
 
 #endif /* KIWMI_LUAK_KIWMI_LUA_CALLBACK_H */

include/luak/luak.h

@@ -16,10 +16,30 @@
 
 struct kiwmi_lua {
     lua_State *L;
-    struct wl_list callbacks; // lua_callback::link
+    int objects;
     struct wl_global *global;
 };
 
+struct kiwmi_object {
+    struct kiwmi_lua *lua;
+
+    void *object;
+    size_t refcount;
+    bool valid;
+
+    struct wl_listener destroy;
+    struct wl_list callbacks; // struct kiwmi_lua_callback::link
+
+    struct {
+        struct wl_signal destroy;
+    } events;
+};
+
+int luaK_kiwmi_object_gc(lua_State *L);
+struct kiwmi_object *luaK_get_kiwmi_object(
+    struct kiwmi_lua *lua,
+    void *ptr,
+    struct wl_signal *destroy);
 int luaK_callback_register_dispatch(lua_State *L);
 int luaK_usertype_ref_equal(lua_State *L);
 struct kiwmi_lua *luaK_create(struct kiwmi_server *server);

kiwmi/desktop/.output.c.kak.pRsrnt

@@ -0,0 +1,277 @@
+wow such kakoune/* Copyright (c), Charlotte Meyer <dev@buffet.sh>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "desktop/output.h"
+
+#include <stdlib.h>
+
+#include <wayland-server.h>
+#include <wlr/backend.h>
+#include <wlr/render/wlr_renderer.h>
+#include <wlr/types/wlr_layer_shell_v1.h>
+#include <wlr/types/wlr_matrix.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_surface.h>
+#include <wlr/types/wlr_xcursor_manager.h>
+#include <wlr/util/log.h>
+
+#include "desktop/desktop.h"
+#include "desktop/layer_shell.h"
+#include "desktop/view.h"
+#include "input/cursor.h"
+#include "input/input.h"
+#include "server.h"
+
+static void
+render_layer_surface(struct wlr_surface *surface, int x, int y, void *data)
+{
+    struct kiwmi_render_data *rdata = data;
+    struct wlr_output *output       = rdata->output;
+    struct wlr_box *geom            = rdata->data;
+
+    struct wlr_texture *texture = wlr_surface_get_texture(surface);
+    if (!texture) {
+        return;
+    }
+
+    int ox = rdata->output_lx + x + geom->x;
+    int oy = rdata->output_ly + y + geom->y;
+
+    struct wlr_box box = {
+        .x      = ox * output->scale,
+        .y      = oy * output->scale,
+        .width  = surface->current.width * output->scale,
+        .height = surface->current.height * output->scale,
+    };
+
+    float matrix[9];
+    enum wl_output_transform transform =
+        wlr_output_transform_invert(surface->current.transform);
+    wlr_matrix_project_box(
+        matrix, &box, transform, 0, output->transform_matrix);
+
+    wlr_render_texture_with_matrix(rdata->renderer, texture, matrix, 1);
+
+    wlr_surface_send_frame_done(surface, rdata->when);
+}
+
+static void
+render_layer(struct wl_list *layer, struct kiwmi_render_data *rdata)
+{
+    struct kiwmi_layer *surface;
+    wl_list_for_each (surface, layer, link) {
+        rdata->data = &surface->geom;
+
+        wlr_layer_surface_v1_for_each_surface(
+            surface->layer_surface, render_layer_surface, rdata);
+    }
+}
+
+static void
+render_surface(struct wlr_surface *surface, int sx, int sy, void *data)
+{
+    struct kiwmi_render_data *rdata = data;
+    struct kiwmi_view *view         = rdata->data;
+    struct wlr_output *output       = rdata->output;
+
+    struct wlr_texture *texture = wlr_surface_get_texture(surface);
+    if (!texture) {
+        return;
+    }
+
+    int ox = rdata->output_lx + sx + view->x - view->geom.x;
+    int oy = rdata->output_ly + sy + view->y - view->geom.y;
+
+    struct wlr_box box = {
+        .x      = ox * output->scale,
+        .y      = oy * output->scale,
+        .width  = surface->current.width * output->scale,
+        .height = surface->current.height * output->scale,
+    };
+
+    float matrix[9];
+    enum wl_output_transform transform =
+        wlr_output_transform_invert(surface->current.transform);
+    wlr_matrix_project_box(
+        matrix, &box, transform, 0, output->transform_matrix);
+
+    wlr_render_texture_with_matrix(rdata->renderer, texture, matrix, 1);
+
+    wlr_surface_send_frame_done(surface, rdata->when);
+}
+
+static void
+output_frame_notify(struct wl_listener *listener, void *data)
+{
+    struct kiwmi_output *output   = wl_container_of(listener, output, frame);
+    struct wlr_output *wlr_output = data;
+    struct kiwmi_desktop *desktop = output->desktop;
+    struct wlr_output_layout *output_layout = desktop->output_layout;
+    struct wlr_renderer *renderer =
+        wlr_backend_get_renderer(wlr_output->backend);
+
+    struct timespec now;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+
+    if (!wlr_output_attach_render(wlr_output, NULL)) {
+        wlr_log(WLR_ERROR, "Failed to attach renderer to output");
+        return;
+    }
+
+    int width;
+    int height;
+    wlr_output_effective_resolution(wlr_output, &width, &height);
+
+    wlr_renderer_begin(renderer, width, height);
+    wlr_renderer_clear(renderer, (float[]){0.0f, 1.0f, 0.0f, 1.0f});
+
+    double output_lx;
+    double output_ly;
+    wlr_output_layout_output_coords(
+        output_layout, wlr_output, &output_lx, &output_ly);
+
+    struct kiwmi_render_data rdata = {
+        .output    = output->wlr_output,
+        .output_lx = output_lx,
+        .output_ly = output_ly,
+        .renderer  = renderer,
+        .when      = &now,
+    };
+
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND], &rdata);
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM], &rdata);
+
+    struct kiwmi_view *view;
+    wl_list_for_each_reverse (view, &desktop->views, link) {
+        if (view->hidden || !view->mapped) {
+            continue;
+        }
+
+        rdata.data = view;
+
+        wl_signal_emit(&view->events.pre_render, &rdata);
+        view_for_each_surface(view, render_surface, &rdata);
+        wl_signal_emit(&view->events.post_render, &rdata);
+    }
+
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP], &rdata);
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY], &rdata);
+
+    wlr_output_render_software_cursors(wlr_output, NULL);
+    wlr_renderer_end(renderer);
+
+    wlr_output_commit(wlr_output);
+}
+
+static void
+output_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_output *output = wl_container_of(listener, output, destroy);
+
+    wlr_output_layout_remove(
+        output->desktop->output_layout, output->wlr_output);
+
+    wl_signal_emit(&output->events.destroy, output);
+
+    wl_list_remove(&output->link);
+    wl_list_remove(&output->frame.link);
+    wl_list_remove(&output->destroy.link);
+
+    free(output);
+}
+
+static void
+output_mode_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_output *output = wl_container_of(listener, output, mode);
+
+    arrange_layers(output);
+
+    wl_signal_emit(&output->events.resize, output);
+}
+
+static void
+output_transform_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_output *output = wl_container_of(listener, output, transform);
+
+    arrange_layers(output);
+
+    wl_signal_emit(&output->events.resize, output);
+}
+
+static struct kiwmi_output *
+output_create(struct wlr_output *wlr_output, struct kiwmi_desktop *desktop)
+{
+    struct kiwmi_output *output = calloc(1, sizeof(*output));
+    if (!output) {
+        return NULL;
+    }
+
+    output->wlr_output = wlr_output;
+    output->desktop    = desktop;
+
+    output->frame.notify = output_frame_notify;
+    wl_signal_add(&wlr_output->events.frame, &output->frame);
+
+    output->destroy.notify = output_destroy_notify;
+    wl_signal_add(&wlr_output->events.destroy, &output->destroy);
+
+    output->mode.notify = output_mode_notify;
+    wl_signal_add(&wlr_output->events.mode, &output->mode);
+
+    output->transform.notify = output_transform_notify;
+    wl_signal_add(&wlr_output->events.transform, &output->transform);
+
+    return output;
+}
+
+void
+new_output_notify(struct wl_listener *listener, void *data)
+{
+    struct kiwmi_desktop *desktop =
+        wl_container_of(listener, desktop, new_output);
+    struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
+    struct wlr_output *wlr_output = data;
+
+    wlr_log(WLR_DEBUG, "New output %p: %s", wlr_output, wlr_output->name);
+
+    if (!wl_list_empty(&wlr_output->modes)) {
+        struct wlr_output_mode *mode =
+            wl_container_of(wlr_output->modes.prev, mode, link);
+        wlr_output_set_mode(wlr_output, mode);
+    }
+
+    struct kiwmi_output *output = output_create(wlr_output, desktop);
+    if (!output) {
+        wlr_log(WLR_ERROR, "Failed to create output");
+        return;
+    }
+
+    wlr_output->data = output;
+
+    struct kiwmi_cursor *cursor = server->input.cursor;
+
+    wlr_xcursor_manager_load(cursor->xcursor_manager, wlr_output->scale);
+
+    wl_list_insert(&desktop->outputs, &output->link);
+
+    wlr_output_layout_add_auto(desktop->output_layout, wlr_output);
+
+    wlr_output_create_global(wlr_output);
+
+    size_t len_outputs = sizeof(output->layers) / sizeof(output->layers[0]);
+    for (size_t i = 0; i < len_outputs; ++i) {
+        wl_list_init(&output->layers[i]);
+    }
+
+    wl_signal_init(&output->events.destroy);
+    wl_signal_init(&output->events.resize);
+
+    wl_signal_emit(&desktop->events.new_output, output);
+}

kiwmi/desktop/xdg_shell.c

@@ -33,9 +33,12 @@ static void
 xdg_surface_unmap_notify(struct wl_listener *listener, void *UNUSED(data))
 {
     struct kiwmi_view *view = wl_container_of(listener, view, unmap);
-    view->mapped            = false;
 
-    wl_signal_emit(&view->events.unmap, view);
+    if (view->mapped) {
+        view->mapped = false;
+
+        wl_signal_emit(&view->events.unmap, view);
+    }
 }
 
 static void

kiwmi/luak/kiwmi_cursor.c

@@ -23,8 +23,10 @@
 static int
 l_kiwmi_cursor_pos(lua_State *L)
 {
-    struct kiwmi_cursor *cursor =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_cursor **)luaL_checkudata(L, 1, "kiwmi_cursor");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_cursor");
+
+    struct kiwmi_cursor *cursor = obj->object;
 
     lua_pushnumber(L, cursor->cursor->x);
     lua_pushnumber(L, cursor->cursor->y);
@@ -35,9 +37,11 @@ l_kiwmi_cursor_pos(lua_State *L)
 static int
 l_kiwmi_cursor_view_at_pos(lua_State *L)
 {
-    struct kiwmi_cursor *cursor =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_cursor **)luaL_checkudata(L, 1, "kiwmi_cursor");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_cursor");
 
+    struct kiwmi_lua *lua       = obj->lua;
+    struct kiwmi_cursor *cursor = obj->object;
     struct kiwmi_server *server = cursor->server;
 
     struct wlr_surface *surface;
@@ -54,8 +58,9 @@ l_kiwmi_cursor_view_at_pos(lua_State *L)
 
     if (view) {
         lua_pushcfunction(L, luaK_kiwmi_view_new);
+        lua_pushlightuserdata(L, lua);
         lua_pushlightuserdata(L, view);
-        if (lua_pcall(L, 1, 1, 0)) {
+        if (lua_pcall(L, 2, 1, 0)) {
             wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
             return 0;
         }
@@ -130,10 +135,11 @@ kiwmi_cursor_on_motion_notify(struct wl_listener *listener, void *data)
 static int
 l_kiwmi_cursor_on_button_down(lua_State *L)
 {
-    struct kiwmi_cursor *cursor =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_cursor **)luaL_checkudata(L, 1, "kiwmi_cursor");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_cursor");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    struct kiwmi_cursor *cursor = obj->object;
     struct kiwmi_server *server = cursor->server;
 
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
@@ -141,22 +147,24 @@ l_kiwmi_cursor_on_button_down(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_cursor_on_button_down_or_up_notify);
     lua_pushlightuserdata(L, &cursor->events.button_down);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_cursor_on_button_up(lua_State *L)
 {
-    struct kiwmi_cursor *cursor =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_cursor **)luaL_checkudata(L, 1, "kiwmi_cursor");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_cursor");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    struct kiwmi_cursor *cursor = obj->object;
     struct kiwmi_server *server = cursor->server;
 
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
@@ -164,22 +172,24 @@ l_kiwmi_cursor_on_button_up(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_cursor_on_button_down_or_up_notify);
     lua_pushlightuserdata(L, &cursor->events.button_up);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_cursor_on_motion(lua_State *L)
 {
-    struct kiwmi_cursor *cursor =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_cursor **)luaL_checkudata(L, 1, "kiwmi_cursor");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_cursor");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    struct kiwmi_cursor *cursor = obj->object;
     struct kiwmi_server *server = cursor->server;
 
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
@@ -187,13 +197,14 @@ l_kiwmi_cursor_on_motion(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_cursor_on_motion_notify);
     lua_pushlightuserdata(L, &cursor->events.motion);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static const luaL_Reg kiwmi_cursor_events[] = {
@@ -206,15 +217,19 @@ static const luaL_Reg kiwmi_cursor_events[] = {
 int
 luaK_kiwmi_cursor_new(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_cursor
+    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_lua
+    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // kiwmi_cursor
 
-    struct kiwmi_cursor *cursor = lua_touserdata(L, 1);
+    struct kiwmi_lua *lua       = lua_touserdata(L, 1);
+    struct kiwmi_cursor *cursor = lua_touserdata(L, 2);
 
-    struct kiwmi_cursor **cursor_ud = lua_newuserdata(L, sizeof(*cursor_ud));
+    struct kiwmi_object *obj = luaK_get_kiwmi_object(lua, cursor, NULL);
+
+    struct kiwmi_object **cursor_ud = lua_newuserdata(L, sizeof(*cursor_ud));
     luaL_getmetatable(L, "kiwmi_cursor");
     lua_setmetatable(L, -2);
 
-    *cursor_ud = cursor;
+    *cursor_ud = obj;
 
     return 1;
 }
@@ -234,5 +249,8 @@ luaK_kiwmi_cursor_register(lua_State *L)
     lua_pushcfunction(L, luaK_usertype_ref_equal);
     lua_setfield(L, -2, "__eq");
 
+    lua_pushcfunction(L, luaK_kiwmi_object_gc);
+    lua_setfield(L, -2, "__gc");
+
     return 0;
 }

kiwmi/luak/kiwmi_keyboard.c

@@ -19,8 +19,14 @@
 static int
 l_kiwmi_keyboard_modifiers(lua_State *L)
 {
-    struct kiwmi_keyboard *keyboard =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_keyboard **)luaL_checkudata(L, 1, "kiwmi_keyboard");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_keyboard");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_keyboard no longer valid");
+    }
+
+    struct kiwmi_keyboard *keyboard = obj->object;
 
     uint32_t modifiers = wlr_keyboard_get_modifiers(keyboard->device->keyboard);
 
@@ -70,8 +76,9 @@ kiwmi_keyboard_on_destroy_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_keyboard_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, keyboard);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -116,8 +123,9 @@ kiwmi_keyboard_on_key_down_or_up_notify(
         lua_setfield(L, -2, "key");
 
         lua_pushcfunction(L, luaK_kiwmi_keyboard_new);
+        lua_pushlightuserdata(L, server->lua);
         lua_pushlightuserdata(L, keyboard);
-        if (lua_pcall(L, 1, 1, 0)) {
+        if (lua_pcall(L, 2, 1, 0)) {
             wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
             lua_pop(L, 1);
             return;
@@ -138,70 +146,88 @@ kiwmi_keyboard_on_key_down_or_up_notify(
 static int
 l_kiwmi_keyboard_on_destroy(lua_State *L)
 {
-    struct kiwmi_keyboard *keyboard =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_keyboard **)luaL_checkudata(L, 1, "kiwmi_keyboard");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_keyboard");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
-    struct kiwmi_server *server = keyboard->server;
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_keyboard no longer valid");
+    }
+
+    struct kiwmi_keyboard *keyboard = obj->object;
+    struct kiwmi_server *server     = keyboard->server;
 
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_keyboard_on_destroy_notify);
-    lua_pushlightuserdata(L, &keyboard->events.destroy);
+    lua_pushlightuserdata(L, &obj->events.destroy);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_keyboard_on_key_down(lua_State *L)
 {
-    struct kiwmi_keyboard *keyboard =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_keyboard **)luaL_checkudata(L, 1, "kiwmi_keyboard");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_keyboard");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
-    struct kiwmi_server *server = keyboard->server;
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_keyboard no longer valid");
+    }
+
+    struct kiwmi_keyboard *keyboard = obj->object;
+    struct kiwmi_server *server     = keyboard->server;
 
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_keyboard_on_key_down_or_up_notify);
     lua_pushlightuserdata(L, &keyboard->events.key_down);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_keyboard_on_key_up(lua_State *L)
 {
-    struct kiwmi_keyboard *keyboard =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_keyboard **)luaL_checkudata(L, 1, "kiwmi_keyboard");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_keyboard");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
-    struct kiwmi_server *server = keyboard->server;
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_keyboard no longer valid");
+    }
+
+    struct kiwmi_keyboard *keyboard = obj->object;
+    struct kiwmi_server *server     = keyboard->server;
 
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_keyboard_on_key_down_or_up_notify);
     lua_pushlightuserdata(L, &keyboard->events.key_up);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static const luaL_Reg kiwmi_keyboard_events[] = {
@@ -214,16 +240,21 @@ static const luaL_Reg kiwmi_keyboard_events[] = {
 int
 luaK_kiwmi_keyboard_new(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_keyboard
+    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_lua
+    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // kiwmi_keyboard
 
-    struct kiwmi_keyboard *keyboard = lua_touserdata(L, 1);
+    struct kiwmi_lua *lua           = lua_touserdata(L, 1);
+    struct kiwmi_keyboard *keyboard = lua_touserdata(L, 2);
 
-    struct kiwmi_keyboard **keyboard_ud =
+    struct kiwmi_object *obj =
+        luaK_get_kiwmi_object(lua, keyboard, &keyboard->events.destroy);
+
+    struct kiwmi_object **keyboard_ud =
         lua_newuserdata(L, sizeof(*keyboard_ud));
     luaL_getmetatable(L, "kiwmi_keyboard");
     lua_setmetatable(L, -2);
 
-    *keyboard_ud = keyboard;
+    *keyboard_ud = obj;
 
     return 1;
 }
@@ -243,5 +274,8 @@ luaK_kiwmi_keyboard_register(lua_State *L)
     lua_pushcfunction(L, luaK_usertype_ref_equal);
     lua_setfield(L, -2, "__eq");
 
+    lua_pushcfunction(L, luaK_kiwmi_object_gc);
+    lua_setfield(L, -2, "__gc");
+
     return 0;
 }

kiwmi/luak/kiwmi_lua_callback.c

@@ -12,27 +12,6 @@
 #include <lauxlib.h>
 #include <wayland-server.h>
 
-static int
-l_kiwmi_lua_callback_cancel(lua_State *L)
-{
-    struct kiwmi_lua_callback *lc =
-        *(struct kiwmi_lua_callback **)luaL_checkudata(
-            L, 1, "kiwmi_lua_callback");
-
-    wl_list_remove(&lc->listener.link);
-    wl_list_remove(&lc->link);
-
-    luaL_unref(L, LUA_REGISTRYINDEX, lc->callback_ref);
-
-    free(lc);
-    return 0;
-}
-
-static const luaL_Reg kiwmi_lua_callback_methods[] = {
-    {"cancel", l_kiwmi_lua_callback_cancel},
-    {NULL, NULL},
-};
-
 int
 luaK_kiwmi_lua_callback_new(lua_State *L)
 {
@@ -40,18 +19,13 @@ luaK_kiwmi_lua_callback_new(lua_State *L)
     luaL_checktype(L, 2, LUA_TFUNCTION);      // callback
     luaL_checktype(L, 3, LUA_TLIGHTUSERDATA); // event_handler
     luaL_checktype(L, 4, LUA_TLIGHTUSERDATA); // signal
-
+    luaL_checktype(L, 5, LUA_TLIGHTUSERDATA); // object
-    struct kiwmi_lua_callback **lc_ud = lua_newuserdata(L, sizeof(*lc_ud));
-    luaL_getmetatable(L, "kiwmi_lua_callback");
-    lua_setmetatable(L, -2);
 
     struct kiwmi_lua_callback *lc = malloc(sizeof(*lc));
     if (!lc) {
         return luaL_error(L, "failed to allocate kiwmi_lua_callback");
     }
 
-    *lc_ud = lc;
-
     struct kiwmi_server *server = lua_touserdata(L, 1);
 
     lc->server = server;
@@ -62,37 +36,9 @@ luaK_kiwmi_lua_callback_new(lua_State *L)
     lc->listener.notify = lua_touserdata(L, 3);
     wl_signal_add(lua_touserdata(L, 4), &lc->listener);
 
-    wl_list_insert(&server->lua->callbacks, &lc->link);
+    struct kiwmi_object *object = lua_touserdata(L, 5);
 
-    return 1;
+    wl_list_insert(&object->callbacks, &lc->link);
-}
-
-int
-luaK_kiwmi_lua_callback_register(lua_State *L)
-{
-    luaL_newmetatable(L, "kiwmi_lua_callback");
-
-    lua_pushvalue(L, -1);
-    lua_setfield(L, -2, "__index");
-    luaL_setfuncs(L, kiwmi_lua_callback_methods, 0);
-
-    lua_pushcfunction(L, luaK_usertype_ref_equal);
-    lua_setfield(L, -2, "__eq");
 
     return 0;
 }
-
-void
-luaK_kiwmi_lua_callback_cleanup(struct kiwmi_lua *lua)
-{
-    struct kiwmi_lua_callback *lc;
-    struct kiwmi_lua_callback *tmp;
-    wl_list_for_each_safe (lc, tmp, &lua->callbacks, link) {
-        wl_list_remove(&lc->listener.link);
-        wl_list_remove(&lc->link);
-
-        luaL_unref(lua->L, LUA_REGISTRYINDEX, lc->callback_ref);
-
-        free(lc);
-    }
-}

kiwmi/luak/kiwmi_output.c

@@ -20,9 +20,14 @@
 static int
 l_kiwmi_output_auto(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output             = obj->object;
     struct wlr_output_layout *output_layout = output->desktop->output_layout;
 
     wlr_output_layout_add_auto(output_layout, output->wlr_output);
@@ -33,11 +38,16 @@ l_kiwmi_output_auto(lua_State *L)
 static int
 l_kiwmi_output_move(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
     luaL_checktype(L, 2, LUA_TNUMBER); // x
     luaL_checktype(L, 3, LUA_TNUMBER); // y
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output             = obj->object;
     struct wlr_output_layout *output_layout = output->desktop->output_layout;
 
     int lx = lua_tonumber(L, 2);
@@ -51,8 +61,14 @@ l_kiwmi_output_move(lua_State *L)
 static int
 l_kiwmi_output_name(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output = obj->object;
 
     lua_pushstring(L, output->wlr_output->name);
 
@@ -62,9 +78,14 @@ l_kiwmi_output_name(lua_State *L)
 static int
 l_kiwmi_output_pos(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output             = obj->object;
     struct wlr_output_layout *output_layout = output->desktop->output_layout;
 
     struct wlr_box *box =
@@ -79,8 +100,14 @@ l_kiwmi_output_pos(lua_State *L)
 static int
 l_kiwmi_output_size(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output = obj->object;
 
     lua_pushinteger(L, output->wlr_output->width);
     lua_pushinteger(L, output->wlr_output->height);
@@ -109,9 +136,10 @@ kiwmi_output_on_destroy_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_output_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, output);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -140,9 +168,10 @@ kiwmi_output_on_resize_notify(struct wl_listener *listener, void *data)
     lua_newtable(L);
 
     lua_pushcfunction(L, luaK_kiwmi_output_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, output);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -165,10 +194,15 @@ kiwmi_output_on_resize_notify(struct wl_listener *listener, void *data)
 static int
 l_kiwmi_output_on_destroy(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output   = obj->object;
     struct kiwmi_desktop *desktop = output->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -176,23 +210,29 @@ l_kiwmi_output_on_destroy(lua_State *L)
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_output_on_destroy_notify);
-    lua_pushlightuserdata(L, &output->events.destroy);
+    lua_pushlightuserdata(L, &obj->events.destroy);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_output_on_resize(lua_State *L)
 {
-    struct kiwmi_output *output =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_output **)luaL_checkudata(L, 1, "kiwmi_output");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output   = obj->object;
     struct kiwmi_desktop *desktop = output->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -201,13 +241,14 @@ l_kiwmi_output_on_resize(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_output_on_resize_notify);
     lua_pushlightuserdata(L, &output->events.resize);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static const luaL_Reg kiwmi_output_events[] = {
@@ -219,15 +260,20 @@ static const luaL_Reg kiwmi_output_events[] = {
 int
 luaK_kiwmi_output_new(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_output
+    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_lua
+    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // kiwmi_output
 
-    struct kiwmi_output *output = lua_touserdata(L, 1);
+    struct kiwmi_lua *lua       = lua_touserdata(L, 1);
+    struct kiwmi_output *output = lua_touserdata(L, 2);
 
-    struct kiwmi_output **output_ud = lua_newuserdata(L, sizeof(*output_ud));
+    struct kiwmi_object *obj =
+        luaK_get_kiwmi_object(lua, output, &output->events.destroy);
+
+    struct kiwmi_object **output_ud = lua_newuserdata(L, sizeof(*output_ud));
     luaL_getmetatable(L, "kiwmi_output");
     lua_setmetatable(L, -2);
 
-    *output_ud = output;
+    *output_ud = obj;
 
     return 1;
 }
@@ -247,5 +293,8 @@ luaK_kiwmi_output_register(lua_State *L)
     lua_pushcfunction(L, luaK_usertype_ref_equal);
     lua_setfield(L, -2, "__eq");
 
+    lua_pushcfunction(L, luaK_kiwmi_object_gc);
+    lua_setfield(L, -2, "__gc");
+
     return 0;
 }

kiwmi/luak/kiwmi_renderer.c

@@ -93,11 +93,13 @@ static const luaL_Reg kiwmi_renderer_methods[] = {
 int
 luaK_kiwmi_renderer_new(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // wlr_renderer
+    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_lua
-    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // wlr_output
+    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // wlr_renderer
+    luaL_checktype(L, 3, LUA_TLIGHTUSERDATA); // wlr_output
 
-    struct wlr_renderer *wlr_renderer = lua_touserdata(L, 1);
+    struct kiwmi_lua *UNUSED(lua)     = lua_touserdata(L, 1);
-    struct kiwmi_output *output       = lua_touserdata(L, 2);
+    struct wlr_renderer *wlr_renderer = lua_touserdata(L, 2);
+    struct kiwmi_output *output       = lua_touserdata(L, 3);
 
     struct kiwmi_renderer *renderer_ud =
         lua_newuserdata(L, sizeof(*renderer_ud));
@@ -122,5 +124,8 @@ luaK_kiwmi_renderer_register(lua_State *L)
     lua_pushcfunction(L, luaK_usertype_ref_equal);
     lua_setfield(L, -2, "__eq");
 
+    lua_pushcfunction(L, luaK_kiwmi_object_gc);
+    lua_setfield(L, -2, "__gc");
+
     return 0;
 }

kiwmi/luak/kiwmi_server.c

@@ -30,12 +30,15 @@
 static int
 l_kiwmi_server_cursor(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
+
+    struct kiwmi_server *server = obj->object;
 
     lua_pushcfunction(L, luaK_kiwmi_cursor_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, server->input.cursor);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
@@ -46,16 +49,19 @@ l_kiwmi_server_cursor(lua_State *L)
 static int
 l_kiwmi_server_focused_view(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
+
+    struct kiwmi_server *server = obj->object;
 
     if (!server->input.seat->focused_view) {
         return 0;
     }
 
     lua_pushcfunction(L, luaK_kiwmi_view_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, server->input.seat->focused_view);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
@@ -66,8 +72,10 @@ l_kiwmi_server_focused_view(lua_State *L)
 static int
 l_kiwmi_server_quit(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
+
+    struct kiwmi_server *server = obj->object;
 
     wl_display_terminate(server->wl_display);
 
@@ -101,8 +109,10 @@ l_kiwmi_server_spawn(lua_State *L)
 static int
 l_kiwmi_server_stop_interactive(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
+
+    struct kiwmi_server *server = obj->object;
 
     server->input.cursor->cursor_mode = KIWMI_CURSOR_PASSTHROUGH;
 
@@ -112,11 +122,13 @@ l_kiwmi_server_stop_interactive(lua_State *L)
 static int
 l_kiwmi_server_view_at(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
     luaL_checktype(L, 2, LUA_TNUMBER); // x
     luaL_checktype(L, 3, LUA_TNUMBER); // y
 
+    struct kiwmi_server *server = obj->object;
+
     double x = lua_tonumber(L, 2);
     double y = lua_tonumber(L, 3);
 
@@ -129,8 +141,9 @@ l_kiwmi_server_view_at(lua_State *L)
 
     if (view) {
         lua_pushcfunction(L, luaK_kiwmi_view_new);
+        lua_pushlightuserdata(L, obj->lua);
         lua_pushlightuserdata(L, view);
-        if (lua_pcall(L, 1, 1, 0)) {
+        if (lua_pcall(L, 2, 1, 0)) {
             wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
             return 0;
         }
@@ -163,8 +176,9 @@ kiwmi_server_on_keyboard_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_keyboard_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, keyboard);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -187,8 +201,9 @@ kiwmi_server_on_output_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_output_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, output);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -211,8 +226,9 @@ kiwmi_server_on_view_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_view_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, view);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -227,64 +243,73 @@ kiwmi_server_on_view_notify(struct wl_listener *listener, void *data)
 static int
 l_kiwmi_server_on_keyboard(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    struct kiwmi_server *server = obj->object;
+
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_server_on_keyboard_notify);
     lua_pushlightuserdata(L, &server->input.events.keyboard_new);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_server_on_output(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    struct kiwmi_server *server = obj->object;
+
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_server_on_output_notify);
     lua_pushlightuserdata(L, &server->desktop.events.new_output);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_server_on_view(lua_State *L)
 {
-    struct kiwmi_server *server =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_server **)luaL_checkudata(L, 1, "kiwmi_server");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    struct kiwmi_server *server = obj->object;
+
     lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_server_on_view_notify);
     lua_pushlightuserdata(L, &server->desktop.events.view_map);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static const luaL_Reg kiwmi_server_events[] = {
@@ -297,15 +322,19 @@ static const luaL_Reg kiwmi_server_events[] = {
 int
 luaK_kiwmi_server_new(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_server
+    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_lua
+    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // kiwmi_server
 
-    struct kiwmi_server *server = lua_touserdata(L, 1);
+    struct kiwmi_lua *lua       = lua_touserdata(L, 1);
+    struct kiwmi_server *server = lua_touserdata(L, 2);
 
-    struct kiwmi_server **server_ud = lua_newuserdata(L, sizeof(*server_ud));
+    struct kiwmi_object *obj = luaK_get_kiwmi_object(lua, server, NULL);
+
+    struct kiwmi_object **server_ud = lua_newuserdata(L, sizeof(*server_ud));
     luaL_getmetatable(L, "kiwmi_server");
     lua_setmetatable(L, -2);
 
-    *server_ud = server;
+    *server_ud = obj;
 
     return 1;
 }
@@ -325,5 +354,8 @@ luaK_kiwmi_server_register(lua_State *L)
     lua_pushcfunction(L, luaK_usertype_ref_equal);
     lua_setfield(L, -2, "__eq");
 
+    lua_pushcfunction(L, luaK_kiwmi_object_gc);
+    lua_setfield(L, -2, "__gc");
+
     return 0;
 }

kiwmi/luak/kiwmi_view.c

@@ -27,8 +27,14 @@
 static int
 l_kiwmi_view_app_id(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     lua_pushstring(L, view_get_app_id(view));
 
@@ -38,8 +44,14 @@ l_kiwmi_view_app_id(lua_State *L)
 static int
 l_kiwmi_view_close(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     view_close(view);
 
@@ -49,10 +61,16 @@ l_kiwmi_view_close(lua_State *L)
 static int
 l_kiwmi_view_csd(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TBOOLEAN);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
+
     struct kiwmi_xdg_decoration *decoration = view->decoration;
     if (!decoration) {
         return 0;
@@ -73,9 +91,14 @@ l_kiwmi_view_csd(lua_State *L)
 static int
 l_kiwmi_view_focus(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view       = obj->object;
     struct kiwmi_desktop *desktop = view->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
     struct kiwmi_seat *seat       = server->input.seat;
@@ -88,8 +111,14 @@ l_kiwmi_view_focus(lua_State *L)
 static int
 l_kiwmi_view_hidden(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     lua_pushboolean(L, view->hidden);
 
@@ -99,8 +128,14 @@ l_kiwmi_view_hidden(lua_State *L)
 static int
 l_kiwmi_view_hide(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     view->hidden = true;
 
@@ -110,8 +145,14 @@ l_kiwmi_view_hide(lua_State *L)
 static int
 l_kiwmi_view_imove(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     view_move(view);
 
@@ -121,10 +162,16 @@ l_kiwmi_view_imove(lua_State *L)
 static int
 l_kiwmi_view_iresize(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TTABLE);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
+
     enum wlr_edges edges = WLR_EDGE_NONE;
 
     lua_pushnil(L);
@@ -162,8 +209,14 @@ l_kiwmi_view_iresize(lua_State *L)
 static int
 l_kiwmi_view_move(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     luaL_checktype(L, 2, LUA_TNUMBER);
     luaL_checktype(L, 3, LUA_TNUMBER);
@@ -177,8 +230,14 @@ l_kiwmi_view_move(lua_State *L)
 static int
 l_kiwmi_view_pid(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     lua_pushinteger(L, view_get_pid(view));
 
@@ -188,8 +247,14 @@ l_kiwmi_view_pid(lua_State *L)
 static int
 l_kiwmi_view_pos(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     lua_pushinteger(L, view->x);
     lua_pushinteger(L, view->y);
@@ -200,11 +265,17 @@ l_kiwmi_view_pos(lua_State *L)
 static int
 l_kiwmi_view_resize(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TNUMBER); // w
     luaL_checktype(L, 3, LUA_TNUMBER); // h
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
+
     double w = lua_tonumber(L, 2);
     double h = lua_tonumber(L, 3);
 
@@ -216,8 +287,14 @@ l_kiwmi_view_resize(lua_State *L)
 static int
 l_kiwmi_view_show(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     view->hidden = false;
 
@@ -227,8 +304,14 @@ l_kiwmi_view_show(lua_State *L)
 static int
 l_kiwmi_view_size(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     uint32_t width;
     uint32_t height;
@@ -243,8 +326,14 @@ l_kiwmi_view_size(lua_State *L)
 static int
 l_kiwmi_view_tiled(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
 
     if (lua_isboolean(L, 2)) {
         enum wlr_edges edges = WLR_EDGE_NONE;
@@ -300,10 +389,16 @@ l_kiwmi_view_tiled(lua_State *L)
 static int
 l_kiwmi_view_title(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
 
-    lua_pushstring(L, view_get_app_id(view));
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view = obj->object;
+
+    lua_pushstring(L, view_get_title(view));
 
     return 1;
 }
@@ -340,9 +435,10 @@ kiwmi_view_on_destroy_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_view_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, view);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -371,9 +467,10 @@ kiwmi_view_on_render_notify(struct wl_listener *listener, void *data)
     lua_newtable(L);
 
     lua_pushcfunction(L, luaK_kiwmi_view_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, view);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -382,9 +479,10 @@ kiwmi_view_on_render_notify(struct wl_listener *listener, void *data)
     lua_setfield(L, -2, "view");
 
     lua_pushcfunction(L, luaK_kiwmi_output_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, output);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -393,10 +491,11 @@ kiwmi_view_on_render_notify(struct wl_listener *listener, void *data)
     lua_setfield(L, -2, "output");
 
     lua_pushcfunction(L, luaK_kiwmi_renderer_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, renderer);
     lua_pushlightuserdata(L, output);
 
-    if (lua_pcall(L, 2, 1, 0)) {
+    if (lua_pcall(L, 3, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -421,9 +520,10 @@ kiwmi_view_on_request_move_notify(struct wl_listener *listener, void *data)
     lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
 
     lua_pushcfunction(L, luaK_kiwmi_view_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, view);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -450,9 +550,10 @@ kiwmi_view_on_request_resize_notify(struct wl_listener *listener, void *data)
     lua_newtable(L);
 
     lua_pushcfunction(L, luaK_kiwmi_view_new);
+    lua_pushlightuserdata(L, server->lua);
     lua_pushlightuserdata(L, view);
 
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_pop(L, 1);
         return;
@@ -494,10 +595,15 @@ kiwmi_view_on_request_resize_notify(struct wl_listener *listener, void *data)
 static int
 l_kiwmi_view_on_destroy(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view       = obj->object;
     struct kiwmi_desktop *desktop = view->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -505,23 +611,29 @@ l_kiwmi_view_on_destroy(lua_State *L)
     lua_pushlightuserdata(L, server);
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_view_on_destroy_notify);
-    lua_pushlightuserdata(L, &view->events.unmap);
+    lua_pushlightuserdata(L, &obj->events.destroy);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_view_on_post_render(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view       = obj->object;
     struct kiwmi_desktop *desktop = view->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -530,22 +642,28 @@ l_kiwmi_view_on_post_render(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_view_on_render_notify);
     lua_pushlightuserdata(L, &view->events.post_render);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_view_on_pre_render(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view       = obj->object;
     struct kiwmi_desktop *desktop = view->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -554,22 +672,28 @@ l_kiwmi_view_on_pre_render(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_view_on_render_notify);
     lua_pushlightuserdata(L, &view->events.pre_render);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_view_on_request_move(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view       = obj->object;
     struct kiwmi_desktop *desktop = view->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -578,22 +702,28 @@ l_kiwmi_view_on_request_move(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_view_on_request_move_notify);
     lua_pushlightuserdata(L, &view->events.request_move);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static int
 l_kiwmi_view_on_request_resize(lua_State *L)
 {
-    struct kiwmi_view *view =
+    struct kiwmi_object *obj =
-        *(struct kiwmi_view **)luaL_checkudata(L, 1, "kiwmi_view");
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_view");
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_view no longer valid");
+    }
+
+    struct kiwmi_view *view       = obj->object;
     struct kiwmi_desktop *desktop = view->desktop;
     struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
 
@@ -602,13 +732,14 @@ l_kiwmi_view_on_request_resize(lua_State *L)
     lua_pushvalue(L, 2);
     lua_pushlightuserdata(L, kiwmi_view_on_request_resize_notify);
     lua_pushlightuserdata(L, &view->events.request_resize);
+    lua_pushlightuserdata(L, obj);
 
-    if (lua_pcall(L, 4, 1, 0)) {
+    if (lua_pcall(L, 5, 0, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         return 0;
     }
 
-    return 1;
+    return 0;
 }
 
 static const luaL_Reg kiwmi_view_events[] = {
@@ -623,15 +754,20 @@ static const luaL_Reg kiwmi_view_events[] = {
 int
 luaK_kiwmi_view_new(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_view
+    luaL_checktype(L, 1, LUA_TLIGHTUSERDATA); // kiwmi_lua
+    luaL_checktype(L, 2, LUA_TLIGHTUSERDATA); // kiwmi_view
 
-    struct kiwmi_view *view = lua_touserdata(L, 1);
+    struct kiwmi_lua *lua   = lua_touserdata(L, 1);
+    struct kiwmi_view *view = lua_touserdata(L, 2);
 
-    struct kiwmi_view **view_ud = lua_newuserdata(L, sizeof(*view_ud));
+    struct kiwmi_object *obj =
+        luaK_get_kiwmi_object(lua, view, &view->events.unmap);
+
+    struct kiwmi_object **view_ud = lua_newuserdata(L, sizeof(*view_ud));
     luaL_getmetatable(L, "kiwmi_view");
     lua_setmetatable(L, -2);
 
-    *view_ud = view;
+    *view_ud = obj;
 
     return 1;
 }
@@ -651,5 +787,8 @@ luaK_kiwmi_view_register(lua_State *L)
     lua_pushcfunction(L, luaK_usertype_ref_equal);
     lua_setfield(L, -2, "__eq");
 
+    lua_pushcfunction(L, luaK_kiwmi_object_gc);
+    lua_setfield(L, -2, "__gc");
+
     return 0;
 }

kiwmi/luak/luak.c

@@ -22,10 +22,108 @@
 #include "luak/kiwmi_server.h"
 #include "luak/kiwmi_view.h"
 
+int
+luaK_kiwmi_object_gc(lua_State *L)
+{
+    struct kiwmi_object *obj = *(struct kiwmi_object **)lua_touserdata(L, 1);
+
+    --obj->refcount;
+
+    if (obj->refcount == 0 && wl_list_empty(&obj->callbacks)) {
+        free(obj);
+    }
+
+    return 0;
+}
+
+static void
+kiwmi_object_destroy_notify(struct wl_listener *listener, void *data)
+{
+    struct kiwmi_object *obj = wl_container_of(listener, obj, destroy);
+
+    wl_signal_emit(&obj->events.destroy, data);
+
+    struct kiwmi_lua_callback *lc;
+    struct kiwmi_lua_callback *tmp;
+    wl_list_for_each_safe (lc, tmp, &obj->callbacks, link) {
+        wl_list_remove(&lc->listener.link);
+        wl_list_remove(&lc->link);
+
+        luaL_unref(lc->server->lua->L, LUA_REGISTRYINDEX, lc->callback_ref);
+
+        free(lc);
+    }
+
+    wl_list_remove(&obj->destroy.link);
+
+    lua_State *L = obj->lua->L;
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, obj->lua->objects);
+    lua_pushlightuserdata(L, obj->object);
+    lua_pushnil(L);
+    lua_settable(L, -3);
+    lua_pop(L, 1);
+
+    obj->valid = false;
+
+    if (obj->refcount == 0) {
+        free(obj);
+    }
+}
+
+struct kiwmi_object *
+luaK_get_kiwmi_object(
+    struct kiwmi_lua *lua,
+    void *ptr,
+    struct wl_signal *destroy)
+{
+    lua_State *L = lua->L;
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, lua->objects);
+    lua_pushlightuserdata(L, ptr);
+    lua_gettable(L, -2);
+
+    struct kiwmi_object *obj = lua_touserdata(L, -1);
+
+    lua_pop(L, 2);
+
+    if (obj) {
+        ++obj->refcount;
+        return obj;
+    }
+
+    obj = malloc(sizeof(*obj));
+    if (!obj) {
+        wlr_log(WLR_ERROR, "Failed to allocate kiwmi_object");
+        return NULL;
+    }
+
+    obj->lua      = lua;
+    obj->object   = ptr;
+    obj->refcount = 1;
+    obj->valid    = true;
+
+    if (destroy) {
+        obj->destroy.notify = kiwmi_object_destroy_notify;
+        wl_signal_add(destroy, &obj->destroy);
+
+        wl_signal_init(&obj->events.destroy);
+    }
+
+    wl_list_init(&obj->callbacks);
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, lua->objects);
+    lua_pushlightuserdata(L, ptr);
+    lua_pushlightuserdata(L, obj);
+    lua_settable(L, -3);
+
+    return obj;
+}
+
 int
 luaK_callback_register_dispatch(lua_State *L)
 {
-    luaL_checktype(L, 1, LUA_TUSERDATA); // server
+    luaL_checktype(L, 1, LUA_TUSERDATA); // object
     luaL_checktype(L, 2, LUA_TSTRING);   // type
     luaL_checktype(L, 3, LUA_TFUNCTION); // callback
 
@@ -77,8 +175,14 @@ luaK_create(struct kiwmi_server *server)
         return NULL;
     }
 
+    lua->L = L;
+
     luaL_openlibs(L);
 
+    // init object registry
+    lua_newtable(L);
+    lua->objects = luaL_ref(L, LUA_REGISTRYINDEX);
+
     // register types
     int error = 0;
 
@@ -86,8 +190,6 @@ luaK_create(struct kiwmi_server *server)
     error |= lua_pcall(L, 0, 0, 0);
     lua_pushcfunction(L, luaK_kiwmi_keyboard_register);
     error |= lua_pcall(L, 0, 0, 0);
-    lua_pushcfunction(L, luaK_kiwmi_lua_callback_register);
-    error |= lua_pcall(L, 0, 0, 0);
     lua_pushcfunction(L, luaK_kiwmi_output_register);
     error |= lua_pcall(L, 0, 0, 0);
     lua_pushcfunction(L, luaK_kiwmi_renderer_register);
@@ -100,14 +202,14 @@ luaK_create(struct kiwmi_server *server)
     if (error) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_close(L);
-        free(lua);
         return NULL;
     }
 
     // create kiwmi global
     lua_pushcfunction(L, luaK_kiwmi_server_new);
+    lua_pushlightuserdata(L, lua);
     lua_pushlightuserdata(L, server);
-    if (lua_pcall(L, 1, 1, 0)) {
+    if (lua_pcall(L, 2, 1, 0)) {
         wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
         lua_close(L);
         free(lua);
@@ -115,10 +217,6 @@ luaK_create(struct kiwmi_server *server)
     }
     lua_setglobal(L, "kiwmi");
 
-    lua->L = L;
-
-    wl_list_init(&lua->callbacks);
-
     if (!luaK_ipc_init(server, lua)) {
         wlr_log(WLR_ERROR, "Failed to initialize IPC");
         lua_close(L);
@@ -148,8 +246,6 @@ luaK_dofile(struct kiwmi_lua *lua, const char *config_path)
 void
 luaK_destroy(struct kiwmi_lua *lua)
 {
-    luaK_kiwmi_lua_callback_cleanup(lua);
-
     lua_close(lua->L);
 
     free(lua);

lua_docs.md

@@ -143,12 +143,6 @@ The compositor will not forward it to the focused view in that case.
 
 A handle to a registered callback.
 
-### Methods
-
-#### callback:cancel()
-
-Unregisters the callback.
-
 ## kiwmi_output
 
 Represents an output (most often a display).